OK issue is fixed based on a response on POTN
I was mounting the TC on to the camera, and then mounting the lens onto the TC and it didn't register the lens.
The solution was to mount the TC and lens together first, then mount the Lens+TC combo onto the camera, and bada-bing!
Thanks for the help guys, I figured it was either a big, bad problem, or something really dumb. Turns out, it was something really dumb!
